1. Field of the Invention
This invention relates to an automotive window assembly retention system for motor vehicle windows which are fixed (i.e. stationary) with respect to the vehicle body. Specifically the invention relates to a resilient retention element capable of being bonded to a window and adapted to engage the periphery of a rabbet frame flange around the window aperture within the vehicle body to facilitate assembly of the window thereto.
2. Description of the Prior Art
It is well known to attach a rubber or polyvinyl chloride (PVC) base to a glass or plastic window assembly either by using adhesives or by molding the base onto the window assembly. The base includes retention elements formed thereon that engage the rabbet flange on the vehicle body and hold the window to the body. Normally the retention elements are all resiliently engaged in the periphery of the window rabbet frame, which resiliency is a function of the retention element material, the base material and the type of interconnection formed between the retention element and the base.
Many non-movable windows used in modern automobiles utilize a modular window design in which a flexible base material is molded in place about the periphery of the window. These so-called modular window assemblies have been found desirable by automotive designers and manufacturers since they readily permit positioning of the outer surface of the window glass close to the outer surface of the automobile body to give a flush appearance and enhance the vehicle aerodynamics. These modular window assemblies are placed, during the assembly of the vehicle, in apertures in the vehicle body formed as body panel rabbet flanges.
The insertion of the modular window assemblies takes place in a moving assembly line prior to the final curing of adhesive which secures the modular window assembly to that portion of the vehicle body. Since the realities of manufacturing recognize the variation in peripheral fits between the modular window assembly and the body aperture into which the window assembly is inserted, it s necessary to fix the position of the modular window assembly with respect to the body as it moves along the line toward the position in which it is finally adhesively secured. Such handling is also necessary in assembly operations in which the body is stopped for robotic assembly of windows.
In the automobile industry, many clip mechanisms have been utilized to perform this function, particularly in plain fixed or stationary glass assemblies as opposed to modular window assemblies. Exemplary of such cips are those shown in U.S. Pat. Nos. 4,235,056 to Griffin and 4,161,851 to Inamoto et al. Similar clip mechanisms were fixed to the molded outer edge of modular window assemblies to perform the desired function. Such clips included mechanisms in which a leg extended perpendicularly from the glass surface and terminated in a backwardly extending free arm to angularly engage the periphery of the rabbet flange. The use of such clips has not been found to be desirable in that they tend to not positively lock the window in position, as is desired, in a reliable manner.
Another retaining system is disclosed in U.S. Pat. No. 4,712,341 which was issued on Dec. 15, 1987 to Charles F. Harris, Jr. and James C. Coleman. This patent describes a modular window assembly clip for positioning an automotive modular window within the body aperture on which the window rabbet frame is formed. The assembly includes a PVC base bonded to the window and a locking leg portion extending away from the window base toward the interior of the vehicle. The locking leg portion is arranged angularly with respect to the positioning leg portion and terminates in a curvilinear locking surface which, as shown, includes teeth for cam-like locking engagement with the periphery of the flanged body aperture. U.S. Pat. No. 4,700,525, which issued on Oct. 20, 1987 to Nieboer et al, also discloses a molded window panel assembly utilizing a clip-like fastener for attaching the window panel to the aperture or recess in the vehicle body.
When a clip of the type disclosed in U.S. Pat. No. 4,712,341 is formed on the PVC base bonded to the glass panel and is engaged with the flange on the aperture of the vehicle, it resiliently deflects with the teeth portion engaging the periphery of the flange on the vehicle frame. This deflection causes stresses to develop which are highest at the point of connection between the retainer leg and the PVC base. It has been found that in some cases stresses are developed upon initial installation which are sufficient to cause a failure, i e., the leg breaking off at the base. In addition, because of the resiliency of the retainer, after the retainer has been deflected, it does not maintain its retention strength. This is because it is not made of perfectly elastic material and therefore yields during installation so that the retention of the window panel prior to installation of the adhesive or sealant is not maintained in proper alignment with the window aperture.
The problems at initial installation discussed above are aggravated by variations in the periphery of the flange on the vehicle structure, which variations are always present during manufacturing. Thus, when the retainer is engaged with the window frame in the vehicle, it is not unusual for the retention element stem to disengage upon initial installation or to break off during the installation process because of the variations in window aperture sizes. This adds to the difficulty in preventing leakage of the adhesive that is applied on the inside of the window aperture, normally under pressure, around the flange in the aperture and to the front of the window assembly. This adhesive permanently retains the glass in the window aperture after curing, and, if the retainer is released or fails during the curing stage of manufacture, it may actually result in leakage around the window.
The retention system of the present invention overcomes these problems by providing a flexible retention element which can be applied directly to the window panel glass so that the peripheral molding of the prior art may be eliminated. The flexible nature of the retention element allows for greater deflection of the stem thereon without the possibility of breaking during insertion, and even allows the stem to be realigned from the inside of the vehicle after insertion of the window panel assembly.